Heihachi Mishima

In an attempt to eliminate his son's "weakness", Heihachi tossed Kazuya, his then 5-year old son, down a deep ravine, claiming that if he were truly his son, he'd be able to survive the fall and climb back up. Kazuya survived, but only because he made a deal with the Devil. To further motivate Kazuya, Heihachi adopted Chinese orphan Lee and raised him as a rival to his true son. After Kazuya had traveled abroad and became an undefeated champion, Heihachi announced the King of Iron Fist Tournament in order to test him. Kazuya won the tournament, tossed Heihachi off the same cliff and assumed control of the Zaibatsu. Heihachi survived the event, and returned in the second tournament to defeat his son, and tossed Kazuya's body into a volcano to kill him. Later, he created a military force called the Tekken Force. Fifteen years after the end of the second tournament, in Central Mexico ruins they discovered Ogre, a creature with bloodlust for strong fighters. Seeking to create the ultimate lifeform from the creature, Heihachi took in his grandson Jin Kazama, trained him, and four years later announced the third Iron Fist tournament as bait. Ogre arrived and was defeated by Jin, only for Heihachi to in turn betray and attempt to kill him. Jin survived, transformed into a demon, attacked Heihachi and flew away.

Afterwards, Heihachi attempted to combine his own DNA with that of Ogre, but discovered that he would need the Devil Gene as a catalyst, held by both his son and Jin. Unable to find Jin, Heihachi learned Kazuya had been resurrected by G Corporation, a rival company. To lure both to him, he held the fourth King of Iron Fist Tournament with his very company's ownership as the grand prize. After the Tekken Force captured Jin upon arrival, Heihachi faced Kazuya in the finals. Heihachi defeated Kazuya,[4] and led him to his Hon-Maru compound, where Jin was being held captive so they could fight. However Jin was able to defeat both, assumed his demon form and almost killed Heihachi. Stopped by a vision of his mother, Jin instead left, telling Heihachi he owed his life to her, flying through the compound's roof.

Immediately after Jin's departure, an army of Jack-4s built and sent by G Corporation invaded Hon-Maru. Heihachi fought together against them with Kazuya, but Kazuya betrayed and threw his father to the Jack-4s, using the diversion to escape. The Jack-4s piled onto Heihachi and one self-destructed, destroying Hon-Maru and seemingly killing Heihachi. However the blast had instead thrown him for several miles where he remained unconscious for the duration of the fifth tournament. Upon waking up, he made his way back to the Zaibatsu headquarters only for troops to block his path and to learn Jin had taken over the company. As a result he enters the sixth tournament in order to recover control of his company.